perf/x86/rapl: Remove the cpu_to_rapl_pmu() function

Prepare for the addition of RAPL core energy counter support.
Post which, one CPU might be mapped to more than one rapl_pmu
(package/die one and a core one). So, remove the cpu_to_rapl_pmu()
function.

Signed-off-by: Dhananjay Ugwekar <Dhananjay.Ugwekar@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Zhang Rui <rui.zhang@intel.com>
Tested-by: Zhang Rui <rui.zhang@intel.com>
Link: https://lore.kernel.org/r/20241115060805.447565-4-Dhananjay.Ugwekar@amd.com